Avoid redundant git switch in Dockerfile for cleaner and more effic…

[Rufusfavour]

…ient git checkout

The original Dockerfile included a git switch command after cloning the repository, which was redundant since the commit hash could be checked out directly after the clone. This update removes the unnecessary git switch and performs the commit checkout directly with git checkout $COMMIT. This reduces the complexity of the build process and improves clarity.

Summary of Update:

1. Removed the redundant git switch in the op-node build stage.
2. Directly checked out the commit using git checkout $COMMIT after cloning.

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1